Stock-Based Compensation (Details 2) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Schedule of Weighted average fair values of stock option grants
Weighted average fair value of grants	$ 7.17		$ 9.57	$ 13.74
Risk-free interest rate	0.72%		0.86%	2.29%
Expected volatility	54.44%		55.22%	52.25%
Expected life in years	5 years 4 months 2 days		5 years 1 month 24 days	5 years 11 days